[binutils, ARM, 6/16] New BF instruction for Armv8.1-M Mainline

This patch is part of a series of patches to add support for Armv8.1-M Mainline
instructions to binutils.

This patch adds the BF instruction.

ChangeLog entries are as follows:
*** gas/ChangeLog ***

2019-04-15  Sudakshina Das  <sudi.das@arm.com>
             Andre Vieira  <andre.simoesdiasvieira@arm.com>

	* config/tc-arm.c (T16_32_TAB): New entries for bf.
	(do_t_branch_future): New.
	(insns): New instruction for bf.
	* testsuite/gas/arm/armv8_1-m-bf.d: New.
	* testsuite/gas/arm/armv8_1-m-bf.s: New.
	* testsuite/gas/arm/armv8_1-m-bf-bad.s: New.
	* testsuite/gas/arm/armv8_1-m-bf-bad.l: New.
	* testsuite/gas/arm/armv8_1-m-bf-bad.d: New.
	* testsuite/gas/arm/armv8_1-m-bf-rel.d: New.
	* testsuite/gas/arm/armv8_1-m-bf-rel.s: New.

*** ld/ChangeLog ***

2019-04-15  Sudakshina Das  <sudi.das@arm.com>

	* testsuite/ld-arm/bf.s: New.
	* testsuite/ld-arm/bf.d: New.
	* testsuite/ld-arm/arm-elf.exp: Add above test.

*** opcodes/ChangeLog ***

2019-04-15  Sudakshina Das  <sudi.das@arm.com>

	* arm-dis.c (thumb32_opcodes): New instructions for bf.

9 files changed, 142 insertions, 0 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 156881b5573..493a59feb95 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,4 +1,18 @@
 2019-04-15  Sudakshina Das  <sudi.das@arm.com>
+            Andre Vieira  <andre.simoesdiasvieira@arm.com>
+
+	* config/tc-arm.c (T16_32_TAB): New entries for bf.
+	(do_t_branch_future): New.
+	(insns): New instruction for bf.
+	* testsuite/gas/arm/armv8_1-m-bf.d: New.
+	* testsuite/gas/arm/armv8_1-m-bf.s: New.
+	* testsuite/gas/arm/armv8_1-m-bf-bad.s: New.
+	* testsuite/gas/arm/armv8_1-m-bf-bad.l: New.
+	* testsuite/gas/arm/armv8_1-m-bf-bad.d: New.
+	* testsuite/gas/arm/armv8_1-m-bf-rel.d: New.
+	* testsuite/gas/arm/armv8_1-m-bf-rel.s: New.
+
+2019-04-15  Sudakshina Das  <sudi.das@arm.com>
 
 	* config/tc-arm.c (md_pcrel_from_section): New switch case for
 	BFD_RELOC_ARM_THUMB_BF17.
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index d3a21d63575..caba2736c16 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -10505,6 +10505,7 @@ encode_thumb32_addr_mode (int i, bfd_boolean is_t, bfd_boolean is_d)
   X(_asrs,  1000, fa50f000),			\
   X(_b,     e000, f000b000),			\
   X(_bcond, d000, f0008000),			\
+  X(_bf,    0000, f040e001),			\
   X(_bic,   4380, ea200000),			\
   X(_bics,  4380, ea300000),			\
   X(_cmn,   42c0, eb100f00),			\
@@ -13320,6 +13321,51 @@ v8_1_branch_value_check (int val, int nbits, int is_signed)
     return SUCCESS;
 }
 
+/* For branches in Armv8.1-M Mainline.  */
+static void
+do_t_branch_future (void)
+{
+  unsigned long insn = inst.instruction;
+
+  inst.instruction = THUMB_OP32 (inst.instruction);
+  if (inst.operands[0].hasreloc == 0)
+    {
+      if (v8_1_branch_value_check (inst.operands[0].imm, 5, FALSE) == FAIL)
+	as_bad (BAD_BRANCH_OFF);
+
+      inst.instruction |= ((inst.operands[0].imm & 0x1f) >> 1) << 23;
+    }
+  else
+    {
+      inst.relocs[0].type = BFD_RELOC_THUMB_PCREL_BRANCH5;
+      inst.relocs[0].pc_rel = 1;
+    }
+
+  switch (insn)
+    {
+      case T_MNEM_bf:
+	if (inst.operands[1].hasreloc == 0)
+	  {
+	    int val = inst.operands[1].imm;
+	    if (v8_1_branch_value_check (inst.operands[1].imm, 17, TRUE) == FAIL)
+	      as_bad (BAD_BRANCH_OFF);
+
+	    int immA = (val & 0x0001f000) >> 12;
+	    int immB = (val & 0x00000ffc) >> 2;
+	    int immC = (val & 0x00000002) >> 1;
+	    inst.instruction |= (immA << 16) | (immB << 1) | (immC << 11);
+	  }
+	else
+	  {
+	    inst.relocs[1].type = BFD_RELOC_ARM_THUMB_BF17;
+	    inst.relocs[1].pc_rel = 1;
+	  }
+	break;
+
+      default: abort ();
+    }
+}
+
 /* Neon instruction encoder helpers.  */
 
 /* Encodings for the different types for various Neon opcodes.  */
@@ -19538,6 +19584,11 @@ static struct asm_barrier_opt barrier_opt_names[] =
   { mnem, OPS##nops ops, OT_unconditional, 0x0, 0x##top, 0, THUMB_VARIANT, \
     NULL, do_##te }
 
+/* T_MNEM_xyz enumerator variants of ToC.  */
+#define toC(mnem, top, nops, ops, te) \
+  { mnem, OPS##nops ops, OT_csuffix, 0x0, T_MNEM##top, 0, THUMB_VARIANT, NULL, \
+    do_##te }
+
 /* Legacy mnemonics that always have conditional infix after the third
    character.  */
 #define CL(mnem, op, nops, ops, ae)	\
@@ -21623,6 +21674,11 @@ static const struct asm_opcode insns[] =
 #define THUMB_VARIANT & arm_ext_v8m_main
  ToC("vlldm", ec300a00, 1, (RRnpc), rn),
  ToC("vlstm", ec200a00, 1, (RRnpc), rn),
+
+ /* Armv8.1-M Mainline instructions.  */
+#undef  THUMB_VARIANT
+#define THUMB_VARIANT & arm_ext_v8_1m_main
+ toC("bf",     _bf,	2, (EXPs, EXPs),	     t_branch_future),
 };
 #undef ARM_VARIANT
 #undef THUMB_VARIANT
@@ -21633,8 +21689,10 @@ static const struct asm_opcode insns[] =
 #undef cCE
 #undef cCL
 #undef C3E
+#undef C3
 #undef CE
 #undef CM
+#undef CL
 #undef UE
 #undef UF
 #undef UT
@@ -21650,6 +21708,9 @@ static const struct asm_opcode insns[] =
 #undef OPS5
 #undef OPS6
 #undef do_0
+#undef ToC
+#undef toC
+#undef ToU
 
 /* MD interface: bits in the object file.  */
 
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf-bad.d b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.d
new file mode 100644
index 00000000000..d61aad79e9a
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.d
@@ -0,0 +1,4 @@
+#name: Invalid Armv8.1-M Mainline BF instructions
+#source: armv8_1-m-bf-bad.s
+#as: -march=armv8.1-m.main
+#error_output: armv8_1-m-bf-bad.l
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf-bad.l b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.l
new file mode 100644
index 00000000000..3f7ed80a6d0
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.l
@@ -0,0 +1,9 @@
+.*: Assembler messages:
+.*:6: Error: branch out of range or not a multiple of 2
+.*:7: Error: branch out of range or not a multiple of 2
+.*:8: Error: branch out of range or not a multiple of 2
+.*:9: Error: branch out of range or not a multiple of 2
+.*:11: Error: branch out of range or not a multiple of 2
+.*:12: Error: branch out of range or not a multiple of 2
+.*:13: Error: branch out of range or not a multiple of 2
+.*:14: Error: branch out of range or not a multiple of 2
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf-bad.s b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.s
new file mode 100644
index 00000000000..43ef4b1bf92
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf-bad.s
@@ -0,0 +1,14 @@
+	.syntax unified
+	.text
+	.thumb
+foo:
+	# OP0 : Unsigned, 5-bit, even
+	bf  0, 36
+	bf -2, 36
+	bf  3, 36
+	bf 32, 36
+	# OP1 : signed, 17-bit, even
+	bf  2, -5
+	bf  2,  5
+	bf  2,  65536
+	bf  2, -65538
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf-rel.d b/gas/testsuite/gas/arm/armv8_1-m-bf-rel.d
new file mode 100644
index 00000000000..e429c136f2e
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf-rel.d
@@ -0,0 +1,10 @@
+#name: Valid Armv8.1-M Mainline BF instruction with relocation
+#as: -march=armv8.1-m.main
+#objdump: -dr --prefix-addresses --show-raw-insn
+#skip: *-*-pe *-wince-* 
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0[0-9a-f]+ <[^>]+> f0df e7ff 	bf	2, 00000000 <.target>
+			0: R_ARM_THM_BF16	.target
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf-rel.s b/gas/testsuite/gas/arm/armv8_1-m-bf-rel.s
new file mode 100644
index 00000000000..c11c9c177a4
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf-rel.s
@@ -0,0 +1,5 @@
+	.syntax unified
+	.text
+	.thumb
+foo:
+	bf 2, .target
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf.d b/gas/testsuite/gas/arm/armv8_1-m-bf.d
new file mode 100644
index 00000000000..dd30b2a2ff1
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf.d
@@ -0,0 +1,13 @@
+#name: Valid Armv8.1-M Mainline BF instruction
+#as: -march=armv8.1-m.main
+#objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0[0-9a-f]+ <[^>]+> f0c0 e803 	bf	2, 0000000a <foo\+0xa>
+0[0-9a-f]+ <[^>]+> 4609      	mov	r1, r1
+0[0-9a-f]+ <[^>]+> f140 e801 	bf	4, 0000000c <foo\+0xc>
+0[0-9a-f]+ <[^>]+> 460a      	mov	r2, r1
+0[0-9a-f]+ <[^>]+> 4613      	mov	r3, r2
+0[0-9a-f]+ <[^>]+> 4614      	mov	r4, r2
diff --git a/gas/testsuite/gas/arm/armv8_1-m-bf.s b/gas/testsuite/gas/arm/armv8_1-m-bf.s
new file mode 100644
index 00000000000..8c6dac748dc
--- /dev/null
+++ b/gas/testsuite/gas/arm/armv8_1-m-bf.s
@@ -0,0 +1,12 @@
+	.syntax unified
+	.text
+	.thumb
+foo:
+	bf 2, 6
+	mov r1, r1
+	bf .LBranch, .LB2
+	mov r2, r1
+.LB2:
+	mov r3, r2
+.LBranch:
+	mov r4, r2